/* 头部 */
.header{
    background-color: transparent;  //transparent：默认;背景颜色为透明
    position: sticky;  //sticky：粘性定位
    left: 0;
    top: 0;
    width: 100%;
    z-index: 1000;
    padding: 1em 0em;

    .navbar-inverse{
        background-color: transparent;
        border-color: transparent;

        .navbar-nav > li > a{
            color: #fff;
        }
    }

    .logo{
        text-transform: uppercase;  //定义仅有大写字母
        color: #fff;
        transition: all linear .1s;  //过渡样式

        &:hover{
            transform: scale(1.2);
            //transform：变换样式
            //scale：指定对象的2D scale（2D缩放）
        }
    }

    .menu{
        a{
            text-transform: uppercase;  //定义仅有大写字母
            color: #fff;
            transition: all linear .1s;  //过渡样式
            border-bottom: 3px solid transparent;  //transparent(背景颜色为透明)

            span{
                display: inline-block;  //指定对象为内联块元素
                transition: all linear .1s;  //过渡样式
            }

            &:hover{
                border-bottom: 3px solid #fcac45;

                span{
                    transform: scale(1.2);
                    //transform：变换样式
                    //scale：指定对象的2D scale（2D缩放）
                }
            }
        }
    }

    // 响应式兼容  768  max-width
    // 当前屏幕大小 x     x <= 768   max-width:768    x>768  min-width:768px
    @media screen and (max-width: 768px) {
        .menu{
            a{
                text-align: center;
            }
        }
    }
}

/* 底部 */
.footer{
    background: #070707;
    padding: 2em 0em;

    .box{
        display: flex;
        justify-content: space-between;
        align-content: center;
        align-items: center;

        .copyright{
            color: #b2b2b2;
        }

        .links{
            display: flex;
            width: 25%;
            justify-content: space-around;

            a{
                width: 2.5em;
                height: 2.5em;
                border: 3px solid #b2b2b2;
                border-radius: 100%;
                transition: all linear .3s;
                flex-shrink: 0;

                &:hover{
                    transform: translateY(-10px);
                    box-shadow: 0px 0px 10px 5px #b2b2b2;
                }

                img{
                    width: 100%;
                    height: 100%;
                }
            }
        }
    }

    @media screen and (max-width:520px){
        .box{
            flex-wrap: wrap;

            .copyright,.links{
                width: 100%;
            }

            .copyright{
                text-align: center;
                margin-bottom: 1em;
            }
        }
    }
}

/* 返回顶部 */
#gotop {
    position: fixed;
    bottom: 90px;
    right: 0%;
    width: 80px;
    cursor: pointer;
    z-index: -99998;
    opacity: 0;
  
    transition: all linear .4s;
  
    &:hover {
        animation: rubberBand 1s;
    }
  
    @keyframes rubberBand {
        from {
          transform: scale3d(1, 1, 1);
        }
      
        30% {
          transform: scale3d(1.25, 0.75, 1);
        }
      
        40% {
          transform: scale3d(0.75, 1.25, 1);
        }
      
        50% {
          transform: scale3d(1.15, 0.85, 1);
        }
      
        65% {
          transform: scale3d(.95, 1.05, 1);
        }
      
        75% {
          transform: scale3d(1.05, .95, 1);
        }
      
        to {
          transform: scale3d(1, 1, 1);
        }
    }
}